Recently in the study of transcription factors concerned with genes expression in adipocytes differentiation, peroxisome proliferator activated receptor (abbreviated as PPAR hereinafter) has been focused. cDNAs of PPAR were cloned from various kinds of animals, and plural isoform genes were found, particularly in mammals three types of isoforms (α, δ, γ) are known (see J. Steroid Biochem. Molec. Biol., 51, 157 (1994); Gene Expression,. 4, 281 (1995) ; Biochem Biophys. Res. Commun., 224, 431 (1996); Mol. Endocrinology., 6, 1634 (1992)). PPAR γ isoform is predominantly expressed in adipose tissues, immune cells, adrenal gland, spleen, small intestine. PPAR α isoform is mainly expressed in adipose tissue, liver, retina, and δ isoform shows the expression with no tissue specificity, which is widely expressed (see Endocrinology., 137, 354 (1996)).
On the other hand, the following thiazolidine derivatives are known as agents for the treatment of non-insulin dependent diabetes mellitus (NIDDM) and are hypoglycemic agents which are used for the improvement of hyperglycemia in the patients suffering from diabetes. They are also effective for the improvement of hyperinsulinemia, glucose tolerance and decrease of serum lipid and therefore they are thought to be considerably hopeful as agents for the treatment of insulin resistance. 
One of the target proteins in the cells of these thiazolidine derivatives is exactly PPAR γ and it is resolved that they enhance the transcription activity of PPAR γ (see Endocrinology., 137, 4189 (1996); Cell., 83, 803 (1995); Cell., 83, 813 (1995); J. Biol. Chem., 270, 12953 (1995)). Therefore, a PPAR activator (agonist) which enhances its transcription activity is thought to be hopeful as a hypoglycemic agent and/or a hypolipidemic agent. Furthermore, since a PPAR γ agonist is known to promote the expression of PPAR γ protein itself (Genes & Development., 10, 974 (1996)), an agent which increases the expression of PPAR γ protein itself as well as PPAR γ activating agent is also clinically useful.
Among all of nuclear receptors, PPAR γ is related to adipocytes differentiation (see J. Biol. Chem., 212, 5637 (1997) and Cell., 83, 803 (1995)). It is known that thiazolidine derivatives which activate this receptor promote adipocytes differentiation. Recently it was reported that thiazolidine derivatives increase fat mass and cause man to gain weight and to become obese (see Lancet., 349, 952 (1997)). Therefore, it is also thought that antagonists which inhibit PPAR γactivity and agents that decrease the expression of PPAR γ protein itself are also clinically applicable. On the other hand, a compound that phosphorylates PPAR γ protein and decreases its activity is reported (Science., 274, 2100 (1996)). This implies that an agent which does not bind on PPAR γ protein as a ligand, but inhibits its activity is also clinically applicable.
From these, PPAR γ activators (agonists) and PPAR γ regulators for its expression that can increase the expression of the protein itself are expected to be useful as hypoglycemic agents, hypolipidemic agents, preventives and/or remedies for diseases associated with metabolic disorders (diabetes, obesity, syndrome X, hypercholesterolemia, hyperlipoproteinemia, etc.), hyperlipidemia, atherosclerosis, hypertension, circulatory diseases, overeating, etc.
On the other hand, antagonists that inhibit the transcription activity of PPAR γ or PPAR γ regulators that inhibit the expression of the protein itself are expected to be useful as hypoglycemic agents, preventives and/or remedies for diseases associated with metabolic disorders (diabetes, obesity, syndrome X, etc.), hyperlipidemia, atherosclerosis, hypertension, overeating, etc.
The following fibrate compound (e.g. chlofibrate) is known as a hypolipidemic agent. 
It is also resolved that one of the target proteins in the cells of fibrate compounds is PPAR γ (See Nature., 347, 645 (1990); J. Steroid Biochem. Molec. Biol., 51, 157 (1994); Biochemistry., 32, 5598 (1993)). From these facts, PPAR α regulators, which can be activated by fibrate compounds are thought to have a hypolipidemic effect, and so they are expected to be useful as preventives and/or remedies for hyperlipidemia etc.
Besides, it was recently reported that biological activation of PPAR α linked anti-obese effect in the specification of WO 9736579. It was reported that the elevation of high density lipoprotein (HDL) cholesterol and the reduction of low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol and triglyceride were induced by PPAR α activation (J. Lipid Res., 39, 17 (1998)). It was also reported that improvement of fatty acid composition in the blood, hypertension and insulin resistance by the treatment of bezafibrate (one of fibtrate compounds) (Diabetes., 46, 348 (1997)). Therefore, agonists that activate PPAR α and PPAR α regulators that promote expression of PPAR α protein itself are useful as hypolipidemic agents and remedies for hyperlipidemia , and are expected to have HDL cholesterol-elevating effect, LDL cholesterol and/or VLDL cholesterol-lowering effect, inhibition on the progress of atherosclerosis and anti-obese effect. Therefore, they are thought to be hopeful agents for the treatment and/or prevention of diabetes as hypoglycemic agents, for the improvement of hypertension, for the relief from risk factor of syndrome X and for the prevention of occurrence of coronary heart diseases.
On the other hand, few reports are found on ligands that activate PPAR δ significantly or on biological activities associated with PPAR δ.
PPAR δ is sometimes called PPAR β, or it is also called NUCl in human. So far it was shown that in the specification of WO 9601430 hNuC1B (PPAR subtype whose structure is different from that of human NUCl in one amino acid)(inhibited the transcription activities of human PPAR α and thyroid hormone receptor. Recently in the specification of WO 9728149, it was reported that compounds bound to PPAR δ protein with high affinity activated PPAR δ significantly (i.e. agonists) and they had HDL (high density lipoprotein) cholesterol-elevating activity. Therefore, agonists that activate PPAR δ are expected to have HDL cholesterol-elevating effect, and so they are expected to be useful for the inhibition on the progress of atherosclerosis and its treatment, as hypolipidemic agents and/or hypoglycemic agents, for the treatment of hyperlipidemia, as hypoglycemic agents, for the treatment of diabetes, for the relief from risk factor of syndrome X, and for the prevention of occurrence of coronary heart diseases.
The following PPAR regulators have been reported.(1) For example, in the specification of WO 9728115, it is described that a compound of formula (A) (wherein R1A is selected from hydrogen, C3-10 cycloalkyl, etc., R2A is selected from hydrogen, C5-10 aryl, C5-10 heteroaryl, etc., R4A is selected from R2A etc., (ZA—WA—) is ZA—CR6AR7A—R8A, etc., R8A is selected from CR6AR7A, O, S(O)pA, etc., R6A and R7A are each independently, selected from hydrogen, C1-6 alkyl, etc., X1A and X2A are each independently, hydrogen, C1-15 alkyl, halogen, etc., YA is selected from S(O)pA, —O—, etc., Y1A is selected from O, C, etc., ZA is selected from Co2R3A etc., tA and vA are each independently 0 or 1, tA+vA is 1, QA is saturated or unsaturated 2-4 straight-chained hydrocarbon, pA is 0-2, R3A is hydroxy, C1-15 alkoxy, etc.) or a pharmaceutically acceptable salt thereof is a PPAR δ modulator (necessary part is extracted in the explanation of the group). In the specifications of WO 9727857 and WO 9728137, it is described that analogous compounds therewith are also PPAR δ modulators.(2) in the specification of WO 9731907, it is described that a compound of formula (B) (wherein AB is phenyl, said phenyl may be substituted by one or more of halogen, C1-6 alkyl, C1-3 alkoxy, C1-3 fluoroalkoxy, nitrile or —NR7BR8B (R7B and R8B are each independently hydrogen or C1-3 alkyl);BB is 5 or 6- membered hetero ring —Cl-6 alkylene-, said hetero ring may be substituted by Cl-3 alkyl;AlkB is Cl-3 alkylene;R1B is hydrogen or C1-3 alkyl;ZB is selected from —(Cl-3 alkylene)phenyl or —NR3BR4B) or a pharmaceutically acceptable salt thereof has PPAR γ agonist activity (necessary part is extracted in the explanation of the group).(3) In the specification of JP Kokai Hei 9-323982, it is described that a propionic acid derivative of formula (C) (wherein RC is an optionally substituted aromatic hydrocarbon, an optionally substituted cyclic aliphatic hydrocarbon, an optionally substituted hetero ring or an optionally substituted fused hetero ring and R5C is lower alkyl), R4C is hydrogen or lower alkyl, R6C is hydrogen or taken together with R9C to form a double bond, R7′C is hydrogen, hydroxy, carboxy, acyl, optionally substituted alkoxycarbonyl, optionally substituted lower alkyl, optionally substituted carbamoyl, optionally substituted aryloxycarbonyl, optionally substituted aralkyloxycarbonyl or a group represented by formula —YC—R8C (wherein YC is —NH— or oxygen, R8C is optionally substituted acyl, optionally substituted alkoxycarbonyl, aryloxycarbonyl or aralkyloxycarbonyl), R9C is hydrogen, optionally substituted lower alkyl or optionally substituted lower alkoxycarbonyl, R10C is hydroxy, optionally substituted amino, optionally substituted lower alkoxy, optionally substituted lower alkyl, optionally substituted aryloxy or optionally substituted aralkyloxy) or a pharmaceutical composition containing a pharmaceutically acceptable salt thereof has hypoglycemic effect and hypolipidemic effect. In the specifications of JP Kokai Hei 8-325264, JP Kokai Hei 8-325250, WO 9638415 and WO 9800137, it is described that analogous compounds therewith have hypoglycemic effect and hypolipidemic effect.(4) In the specification of JP Kokai Hei 8-104688, it is described that a compound of formula (D) (wherein RD is an optionally substituted hydrocarbon residue or a hetero ring which may be bound through carbon chain(s), nD is 0 or 1, XD is CH or N, YD is a bivalent hydrocarbon residue. R1D and R2D are the same or different to represent hydrogen, halogen, optionally substituted hydroxyl or an optionally substituted hydrocarbon residue, and either of R1D or R2D may be taken attached to a part of YD to form a ring) or a salt thereof has hypoglycemic effect and hypolipidemic effect. In the specification of JP Kokai Sho 61-85372, it is described that analogous compounds therewith also have hypoglycemic effect and hypolipidemic effect.(5) In the specification of JP Kokai Hei 1-143856, it is described that a compound of formula (E) (wherein XE is —CR4E═ or —N═, YE is —CR4E═N—, —N═CR4E—, —CR4E═CR4E—, —O—, —S— or —NR4E—, ZE is —(CH2)nEO—, —(CH2)nES—, etc., R1E is —(CHR7E)nECooR6E etc., nE is each independently 0-5, R2E is each hydrogen, lower alkyl, lower alkoxy, trifluoromethyl, nitro, cyano or halogen, etc., R3E is WE is a bond or —O—, —S— or —NR4E—, mE is 1-15, R4E is each independently hydrogen or lower alkyl, R7E is hydrogen or methyl) or a pharmaceutically acceptable salt thereof has an inhibitory activity against lipoxygenase and a competitive activity against leucotriene.(6) In the specification of JP Kohyo Hei 8-504194, it is described that a compound of formula (F)